Light-emitting element

ABSTRACT

Disclosed according to one embodiment is a light-emitting element comprising: a light-emitting structure comprising a first semiconductor layer, an active layer, and a second semiconductor layer; a second conductive layer electrically connected to the second semiconductor layer; a first conductive layer which is disposed in a plurality of via holes passing through the light-emitting structure and second conductive layer and comprises a plurality of through electrodes electrically connected to the first semiconductor layer; an insulation layer for electrically insulating the plurality of through electrodes from the active layer, second semiconductor layer, and second conductive layer; and an electrode pad disposed in an exposed area of the second conductive layer, wherein the farther away the second conductive layer disposed between the plurality of through electrodes is from the electrode pad, the greater the width of the second conductive layer becomes.

TECHNICAL FIELD

Embodiments of the present disclosure relate to a light-emitting elementhaving improved luminous efficiency.

BACKGROUND ART

A light-emitting diode (LED) is a light-emitting element that emitslight when a current is applied thereto. LEDs can emit light at highefficiency and thus have an excellent energy saving effect.

Recently, a problem with the luminance of LEDs has been significantlyaddressed, and LEDs are being applied in various devices such asbacklight units of liquid crystal display (LCD) devices, electronic signboards, indicators, home appliances, and the like.

An LED includes a first semiconductor layer, a second semiconductorlayer, and an active layer disposed between the first semiconductorlayer and the second semiconductor layer, and an electrode pad is formedby etching a portion of a light-emitting structure.

In this case, a current crowding phenomenon in which luminescencecoupling is relatively strong occurs in a region adjacent to theelectrode pad.

DISCLOSURE Technical Problem

Embodiments of the present disclosure are directed to providing alight-emitting element having improved luminous efficiency.

The scope of the present disclosure is not limited to theabove-described object, and other unmentioned objects may be clearlyunderstood by those skilled in the art from the following descriptions.

Technical Solution

One aspect of the present disclosure provides a light-emitting elementincluding a light-emitting structure including a first semiconductorlayer, an active layer, and a second semiconductor layer, a secondconductive layer electrically connected to the second semiconductorlayer, a first conductive layer including a plurality of throughelectrodes which are disposed in a plurality of via holes passingthrough the light-emitting structure and the second conductive layer andare electrically connected to the first semiconductor layer, aninsulating layer configured to electrically insulate the plurality ofthrough electrodes from the active layer, the second semiconductorlayer, and the second conductive layer, and an electrode pad disposed inan exposed area of the second conductive layer, wherein widths of thesecond conductive layers disposed between the plurality of throughelectrodes may increase going away from the electrode pad.

The insulating layer may include a plurality of first insulating layers,which are respectively disposed in the plurality of via-holes andinsulate the through electrodes from the active layer, the secondsemiconductor layer, and the second conductive layer.

The first insulating layer may include a first adjusting portion, whichis formed on a bottom surface of the via-hole and partially exposes thebottom surface of the via-hole.

The first insulating layer may include second adjusting portionsconfigured to extend from the via-holes to the second semiconductorlayer.

Widths of the plurality of second adjusting portions may decrease goingaway from the electrode pad.

Widths of the plurality of first adjusting portions may be the same.

The second conductive layer may be disposed between the second adjustingportions.

The insulating layer may include a second insulating layer configured toelectrically insulate the plurality of second adjusting portions fromthe first conductive layer.

Distances between the plurality of through electrodes may increase goingaway from the electrode pad, the first insulating layer includes a firstadjusting portion, which is formed on a bottom surface of the via-holeand partially exposes the bottom surface of the via-hole and a secondadjusting portion configured to extend from the via-hole to the secondsemiconductor layer, and widths of the plurality of first adjustingportions may be the same.

Widths of the plurality of second adjusting portions may be the same.

Widths of the plurality of first adjusting portions may decrease goingaway from the electrode pad.

The light-emitting element may further include a conductive substrateelectrically connected to the first conductive layer.

Advantageous Effects

According to embodiments, a current spreading effect of a light-emittingelement is increased so that a uniform luminous efficiency can beattained.

Further, a heat generation characteristic of the light-emitting elementis improved so that the lifetime of the light-emitting element can beincreased.

Various advantages and effects of the present disclosure are not limitedto the above descriptions, and can be more easily understood indescriptions of specific embodiments of the present disclosure.

DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view of a light-emitting element according to a firstembodiment of the present disclosure.

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1.

FIG. 3 is a partially enlarged view of portion S₁ of FIG. 1.

FIGS. 4A to 4F are cross-sectional views illustrating a method ofmanufacturing the light-emitting element according to the firstembodiment of the present disclosure.

FIG. 5 is a plan view of a light-emitting element according to a secondembodiment of the present disclosure.

FIG. 6 is a cross-sectional view taken along line B-B of FIG. 5.

FIG. 7 is a plan view of a light-emitting element according to a thirdembodiment of the present disclosure.

FIG. 8 is a cross-sectional view taken along line C-C of FIG. 7.

FIG. 9 is a partially enlarged view of portion S₂ of FIG. 8.

FIGS. 10A to 10F are cross-sectional views illustrating a method ofmanufacturing the light-emitting element according to the thirdembodiment of the present disclosure.

FIG. 11 is a plan view of a light-emitting element according to a fourthembodiment of the present disclosure.

FIG. 12 is a cross-sectional view taken along line D-D of FIG. 11.

FIG. 13 is a cross-sectional view of a light-emitting element accordingto a fifth embodiment of the present disclosure.

MODES OF THE INVENTION

The present disclosure may be modified in various forms and may have avariety of embodiments, and, therefore, specific embodiments will beillustrated in the drawings. The embodiments, however, are not to betaken in a sense for limiting the present disclosure to the specificembodiments, and should be construed to include modifications,equivalents, or substitutions within the spirit and technical scope ofthe present disclosure.

Also, the terms including ordinal numbers such as “first,” “second,” andthe like used herein can be used to describe various components, but thecomponents are not limited by these terms. The terms are used only forthe purpose of distinguishing one component from another component. Forexample, without departing from the scope of the present disclosure, afirst component may be referred to as a second component, and similarly,the second component may also be referred to as the first component. Theterm “and/or” includes a combination of a plurality of related listeditems or any one item of the plurality of related listed items.

When a component is referred to as being “connected,” or “coupled” toother component, it may be directly connected or coupled to the othercomponent, but it should be understood that another component may existbetween the component and the other component. Contrarily, when acomponent is referred to as being “directly connected,” or “directlycoupled” to other component, it should be understood that anothercomponent may be absent between the component and the other component.

The terms used herein are employed to describe only specific embodimentsand are not intended to limit the present disclosure. Unless the contextclearly dictates otherwise, the singular form includes the plural form.It should be understood that the terms of “comprise” and “have” specifythe presence of stated herein features, numbers, steps, operations,elements, components, or a combination thereof, but do not preclude thepresence or probability of addition of one or more another features,numbers, steps, operations, elements, components, or a combinationthereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. Terms,such as those defined in commonly used dictionaries, should understoodas being interpreted as having a meaning that is consistent with theirmeaning in the context of the relevant art and not being interpreted inan idealized or overly formal sense unless expressly so defined herein.

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the drawings, the same reference numerals aregiven to the same or corresponding components regardless of referencenumerals, and a repetitive description thereof will be omitted.

First Embodiment

FIG. 1 is a plan view of a light-emitting element according to a firstembodiment of the present disclosure, and FIG. 2 is a cross-sectionalview taken along line A-A of FIG. 1.

Referring to FIGS. 1 and 2, a light-emitting element 100A according tothe first embodiment of the present disclosure includes a light-emittingstructure 110, a first conductive layer 130 including a plurality ofthrough electrodes 131 which are electrically connected to a firstsemiconductor layer 111, a second conductive layer 120 which iselectrically connected to a second semiconductor layer 113, aninsulating layer 140 which electrically insulates the plurality ofthrough electrodes 131 from each other, and an electrode pad 160 whichis disposed in an exposed region of the second conductive layer 120.

The light-emitting structure 110 includes the first semiconductor layer111, an active layer 112, and the second semiconductor layer 113. Thereis no limitation on a light emission wavelength band of thelight-emitting structure 110. For example, light emitted from thelight-emitting structure may be an ultraviolet wavelength-band light, avisible light wavelength-band light, or an infrared wavelength-bandlight. Components of each layer may be appropriately adjusted togenerate light of a desired light emission wavelength-band.

The first semiconductor layer 111 may be implemented with a compoundsemiconductor such as a III-V group element, a II-VI group element, orthe like, and the first semiconductor layer 111 may be doped with afirst dopant. The first semiconductor layer 111 may be formed of atleast one of a semiconductor material having a composition formula ofAl_(x)In_(y)Ga_(1-x-y))N (0≤x≤1, 0≤y≤1, and 0≤x+y≤1), InAlGaN, AlGaAs,GaP, GaAs, GaAsP, and AlGaInP, but the present disclosure is not limitedthereto. When the first dopant is an N-type dopant such as Si, Ge, Sn,Se, Te, or the like, the first semiconductor layer 111 doped with thefirst dopant may be an N-type semiconductor layer.

In the drawing, although the first semiconductor layer 111 isillustrated as a single layer, the first semiconductor layer 111 mayhave a multi-layer structure. When the first semiconductor layer 111 hasa multi-layer structure, the first semiconductor layer 111 may furtherinclude an undoped semiconductor layer (not illustrated). The undopedsemiconductor layer is a layer which is formed to improve crystallinityof the first semiconductor layer 111, and may have a lower electricalconductivity than the first semiconductor layer 111 because the layer isnot doped with a dopant.

The active layer 112 is a layer into which electrons (or holes) injectedthrough the first semiconductor layer 111 and holes (or electrons)injected through the second semiconductor layer 113 meet. In the activelayer 112, as the electrons and the holes are recombined, the electronstransition to a lower energy level and light having a wavelengthcorresponding to the transition energy level is generated.

The active layer 112 may have any one of a single well structure, amulti-well structure, a single quantum well (SQW) structure, a multiplequantum well (MQW) structure, a quantum dot structure, and a quantumwire structure, and the structure of the active layer 112 is not limitedthereto.

When the active layer 112 is formed to have a well structure, a welllayer/a barrier layer of the active layer 112 may be formed to includeat least one of paired structures InGaN/GaN, InGaN/InGaN, GaN/AlGaN,InAlGaN/GaN, GaAs(InGaAs)/AlGaAs, or GaP(InGaP)/AlGaP, but the presentdisclosure is not limited thereto. The well layer may be formed of amaterial having a bandgap smaller than a that of the barrier layer.

The second semiconductor layer 113 may be implemented using a compoundsemiconductor such as a III-V group element, a II-VI group element, orthe like, and the second semiconductor layer 113 may be doped with asecond dopant. The second semiconductor layer 113 may be formed of asemiconductor material having a composition formula ofIn_(x)Al_(y)Ga_(1-x-y)N (0≤x≤1, 0≤y≤1, and 0≤x+y≤1), or a materialselected from a group consisting of AlInN, AlGaAs, GaP, GaAs, GaAsP, andAlGaInP. When the second dopant is a P-type dopant such as Mg, Zn, Ca,Sr, Ba, or the like, the second semiconductor layer 113 doped with thesecond dopant may be a P-type semiconductor layer.

The light-emitting structure 110 may include a first semiconductor layer111 which is an N-type semiconductor layer and a second semiconductorlayer 113 which is a P-type semiconductor layer, or may include a firstsemiconductor layer 111 which is a P-type semiconductor layer and asecond semiconductor layer 113 which is an N-type semiconductor layer.

Further, the light-emitting structure 110 may have a structure in whichan N-type or P-type semiconductor layer is further formed between thesecond semiconductor layer 113 and the active layer 112. That is, thelight-emitting structure 110 of the embodiment may be formed to have atleast one of N-P, P-N, N-P-N, and P-N-P junction structures, and mayhave variable structures including an N-type semiconductor layer and aP-type semiconductor layer.

Impurities in the first semiconductor layer 111 and the secondsemiconductor layer 113 may be formed to have a uniform or non-uniformdoping concentration. That is, the light-emitting structure 110 may beformed to have various doping profile, but the present disclosure is notlimited thereto.

An upper surface of the light-emitting structure 110 may have a regularor irregular uneven portion 111 a, but the present disclosure is notlimited thereto. For example, the upper surface of the firstsemiconductor layer 111 may be a flat surface.

The first conductive layer 130 is electrically connected to the firstsemiconductor layer 111. Specifically, the first conductive layer 130may include the plurality of through electrodes 131. The throughelectrodes 131 may be disposed in via-holes 115 formed in thelight-emitting structure 110. The first conductive layer 130 may beelectrically connected to the conductive substrate 150 disposedtherebelow.

The first conductive layer 130 may be formed with a transparentconductive oxide (TCO) film. The TCO film may be one selected from agroup consisting of indium tin oxide (ITO), indium zinc oxide (IZO),aluminum zinc oxide (AZO), aluminum gallium zinc oxide (AGZO), indiumzinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium galliumzinc oxide (IGZO), indium gallium tin oxide (IGTO), antimony tin oxide(ATO), gallium zinc oxide (GZO), IZO nitride (IZON), ZnO, IrO_(x),RuO_(x), NiO, and the like.

The first conductive layer 130 may include an opaque metal such as Ag,Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or the like. Further, thefirst conductive layer 130 may be formed as a single layer or aplurality of layers in which a TCO film and an opaque metal are mixed,but the present disclosure is not limited thereto.

The second conductive layer 120 is electrically connected to the secondsemiconductor layer 113. The second conductive layer 120 may be disposedin regions between the plurality of through electrodes 131. The secondconductive layer 120 may be electrically connected to the electrode pad160 by exposing one region thereof.

The second conductive layer 120 may be formed of a material having ahigh reflectivity such as Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au,Hf, or the like, or may be formed of a mixture of the material having ahigh reflectivity and a transparent conductive material such as IZO,IZTO, IAZO, IGZO, IGTO, AZO, ATO, or the like.

The second conductive layer 120 may further include an ohmic layer. Theohmic layer may include at least one selected from a group consisting ofITO, IZO, indium zinc tin oxide IZTO, IAZO, IGZO, IGTO, AZO, ATO, GZO,IZON, Al—Ga ZnO (AGZO), In—Ga ZnO (IGZO), ZnO, IrO_(x), RuO_(x), NiO,RuO_(x)/ITO, Ni/IrO_(x)/Au, Ni/IrO_(x)/Au/ITO, Ag, Ni, Cr, Ti, Al, Rh,Pd, Ir, Sn, In, Ru, Mg, Zn, Pt, Au, and Hf, but the present disclosureis not limited to these materials.

The insulating layer 140 may be formed of at least one selected from agroup consisting of SiO₂, Si_(x)O_(y), Si₃N₄, Si_(x)N_(y), SiO_(x)N_(y),Al₂O₃, TiO₂, AlN, and the like, but the present disclosure is notlimited thereto.

The insulating layer 140 may include a first insulating layer 141 whichelectrically insulates the through electrodes 131 from the active layer112 and the second semiconductor layer 113, and may include a secondinsulating layer 142 which electrically insulates the second conductivelayer 120 from the first conductive layer 130. Therefore, the insulatinglayer 140 may have an increased thickness in a region in which the firstinsulating layer 141 and the second insulating layer 142 overlap.According to such a configuration, since the second conductive layer 120is formed after the first insulating layer 141 is formed, defects due tomigration of the second conductive layer 120 when the via-holes 115 areformed may be prevented.

However, the present disclosure is not limited thereto, and the firstinsulating layer 141 and the second insulating layer 142 may beintegrally formed. The first insulating layer 141 and the secondinsulating layer 142 may be integrally formed by first forming thesecond conductive layer 120 on the second semiconductor layer 113 andthen forming the via-holes 115.

The plurality of through electrodes 131 may be formed so that areas ofcontact regions (hereinafter, referred to as first regions) thereofelectrically connected to the first semiconductor layer 111 decreasegoing away from the electrode pad 160 (P₃>P₂>P₁). That is, areas offirst regions 131 a of the plurality of through electrodes 131 may bedifferent from each other. A separate ohmic contact electrode may bedisposed in each of the first regions 131 a.

Generally, since density of holes is high in a region adjacent to theelectrode pad 160, luminescence coupling may be relatively strong.Therefore, current crowding may occur in the region adjacent to theelectrode pad 160. On the contrary, since density of holes is low in aregion further away from the electrode pad 160, luminescence couplingmay be relatively weak. Therefore, light emission uniformity in theentire light-emitting element may be reduced.

In the first embodiment of the present disclosure, current crowding maybe reduced by reducing an effective area P₁ of the first region 131 a ina region in which luminescence coupling is strong, that is, a regionclose to the electrode pad 160. With such a configuration, an operatingvoltage V_(f) of the light-emitting element may be reduced.

Further, luminescence coupling may be increased by increasing aneffective area P₃ of the first region 131 a in a region relatively farfrom the electrode pad 160. Therefore, since the luminescence couplingin a region close to the electrode pad 160 becomes relatively lower andthe luminescence coupling in a region far from the electrode pad 160 isincreased, overall uniform light may be emitted.

Referring to FIG. 3, the first region 131 a may be controlled by thefirst insulating layer 141. The first insulating layer 141 may include afirst adjusting portion 141 a which extends to a bottom surface 115 a ofthe through electrode 131, and a second adjusting portion 141 b whichextends from the via-hole 115 to the second semiconductor layer 113.

In the present embodiment, there are no specific limitations on a widthW₂ of the second adjusting portion 141 b. For example, all of widths W₂of the plurality of second adjusting portions 141 b may be the same.Therefore, all of widths W₃ of the plurality of first insulating layers141 may be the same. All widths of the second conductive layers 120disposed between the second adjusting portions 141 b may also be thesame.

The area of the first region 131 a may be adjusted by a width W₁ of thefirst adjusting portion 141 a which extends to the bottom surface 115 aof the via-hole 115. That is, when the width W₁ of the first adjustingportion 141 a increases, the area of the first region 131 a decreases.On the contrary, when the width W₁ of the first adjusting portion 141 adecreases, the area of the first region 131 a increases. The width ofthe first adjusting portion 141 a may be adjusted using a mask patternor the like during manufacturing.

In the drawing, the first region 131 a and the first insulating layer141 are illustrated as a circular shape, but the present disclosure isnot limited thereto. The first region 131 a and the first insulatinglayer 141 may have a polygonal or line shape. Table 1 below is a tableobtained by measuring a change in the areas of the first regions 131 aaccording to distances between three through electrodes 131 and theelectrode pad 160, which are illustrated in FIG. 2. The three throughelectrodes 131 are defined as a first through electrode, a secondthrough electrode, and a third through electrode, in order of closenessto the electrode pad.

TABLE 1 First Second Third Through Through Through Electrode ElectrodeElectrode Distance (μm) 163.8 568.8 973.8 from Electrode Pad Radius (μm)25.0 25.0 25.0 of Via-hole Width (μm) of 12 (100%) 10.3 (85.8%) 7.7(64.2%) First Adjusting Portion Radius (μm) 13 14.7 17.3 of First RegionArea (μm²) 530.9 (100%) 678.9 (127.9%) 940.2 (177.1%) of First Region

Referring to Table 1, it can be seen that the area of the first region131 a of the first through electrode 131 closest to the electrode pad160 is 530.9 μm², while the area of the first region 131 a of the thirdthrough electrode 131 farthest from the electrode pad 160 is 940.2 μm²,a 177% increase. When such an arrangement is provided, light emissionuniformity may be excellent.

It can be seen that the width of the first adjusting portion 141 adecreases by about 5.3 nm as the distance from the first throughelectrode 131 increases by 1 μm. Therefore, the width of the firstadjusting portion 141 a disposed on each of the plurality of throughelectrodes 131 may satisfy the following Expression 1.

L _(n) =L ₁−(D _(n−1) x Y)   [Expression 1]

Here, L_(n) denotes a width of a first adjusting portion disposed on ann^(th) through electrode, L₁ denotes a width of a first adjustingportion of a reference through electrode closest to the electrode pad,D_(n−1) denotes an interval between the n^(th) through electrode and thereference through electrode, and Y denotes a constant which satisfies acondition of 3.0 nm<W<8.0 nm.

Referring to FIG. 4, a method of manufacturing a light-emitting elementaccording to the first embodiment of the present disclosure includesforming the via-holes 115 in the light-emitting structure 110, formingthe first insulating layers 141 in the via-holes 115, forming the secondconductive layer 120 on the second semiconductor layer 113 between thefirst insulating layers 141, forming the second insulating layer 142 onthe second conductive layer 120, forming the first conductive layer 130including the through electrodes 131 disposed in the via-holes 115,forming the conductive substrate 150 electrically connected to the firstconductive layer 130, and forming the electrode pad 160 by exposing aportion of the second conductive layer 120.

Referring to FIG. 4A, in the forming of the light-emitting structure,the first semiconductor layer 111, the active layer 112, and the secondsemiconductor layer 113 are formed on a growth substrate 114, and theplurality of via-holes 115 passing from the second semiconductor layer113 to a portion of the first semiconductor layer 111 are formed.Diameters of the via-holes 115 may be the same.

Referring to FIG. 4B, in the forming of the first insulating layer, thefirst insulating layer 141 may be formed in the via-hole 115 using amask pattern (not illustrated). A thickness of the first insulatinglayer 141 may range from 600 nm to 800 nm, but the present disclosure isnot limited thereto.

The first insulating layer 141 may be formed to extend from a bottomsurface of the via-hole 115 to a portion of the second semiconductorlayer 113. In this case, areas of the first insulating layers 141respectively formed on the bottom surfaces 115 a of the via-holes 115may be different from each other. Specifically, referring to FIG. 4B,exposed areas of the first via-holes 115 may increase going toward theleft (P₃>P₂>P₁).

Referring to FIG. 4C, in the forming of the second conductive layer, thesecond conductive layer 120 may be formed on the second semiconductorlayer 113 exposed between the first insulating layers 141. A thicknessof the second conductive layer 120 may be smaller than the thickness ofthe first insulating layer 141. The thickness of the second conductivelayer 120 may range from 100 nm to 500 nm, but the present disclosure isnot limited thereto.

Then, in the forming of the second insulating layer, the secondinsulating layer 142 may be formed on the second conductive layer 120 toseal the second conductive layer 120. To this end, an end portion of thesecond insulating layer 142 may be in contact with the first insulatinglayer 141. Therefore, a thickness of a portion in which the firstinsulating layer 141 and the second insulating layer 142 are intocontact with each other may increase. A thickness of the secondinsulating layer 142 may range from 200 nm to 500 nm, but the presentdisclosure is not limited thereto.

Referring to FIG. 4D, in the forming of the first conductive layer 130,the plurality of via-holes 115 are filled with electrodes to form thethrough electrode 131. With the above-described configuration, the areasof the first regions of the through electrodes 131 may increase goingtoward the left (P₃>P₂>P₁).

Referring to FIG. 4E, in the forming of the conductive substrate 150,the conductive substrate 150 is formed on the first conductive layer130. In this case, the insulating substrate 114 of the light-emittingstructure 110 may be removed. A laser lift-off method may be used as amethod of removing the insulating substrate 114, but the presentdisclosure is not limited thereto. In this case, an uneven portion maybe formed on an upper surface of the light-emitting structure 110 asnecessary.

Referring to FIG. 4F, in the forming of the electrode pad, one side ofthe light-emitting structure 110 is etched (M) to expose the secondconductive layer 120, and the electrode pad 160 is then formed thereon.A protective layer 170 may be formed on side surfaces of thelight-emitting structure 110.

Second Embodiment

FIG. 5 is a plan view of a light-emitting element according to a secondembodiment of the present disclosure, and FIG. 6 is a cross-sectionalview taken along line B-B of FIG. 5.

Referring to FIGS. 5 and 6, a light-emitting element 100B according tothe second embodiment of the present disclosure includes alight-emitting structure 110 including a first semiconductor layer 111,an active layer 112, and a second semiconductor layer 113, a firstconductive layer 130 including a plurality of through electrodes 131electrically connected to the first semiconductor layer 111, a secondconductive layer 120 electrically connected to the second semiconductorlayer 113, an insulating layer 140 which electrically insulates theplurality of through electrodes 131 from each other, and an electrodepad 160 disposed in an exposed region of the second conductive layer120.

The components may be the same as those in the first embodimentdescribed above, but a configuration in which an area of a first region131 a is adjusted is different from that in the first embodimentdescribed above. Therefore, the configuration in which the area of thefirst region 131 a is adjusted will be described in detail.

Diameters of upper end portions of the plurality of through electrodes131 may increase going away from the electrode pad 160 (P₆>P₅>P₄).Therefore, when widths of first adjusting portions 141 a of theinsulating layers 140 are the same, areas of the first regions 131 a ofthe through electrodes 131 increase. That is, exposed areas may beadjusted by changing the diameters of the upper end portions of thethrough electrodes 131. Such a structure has the same effect as that inthe first embodiment described above, and has an advantage in that anexisting mask pattern may be used as is.

Table 2 below is a table obtained by measuring a change in the areas ofthe first regions 131 a according to distances between three throughelectrodes 131 and the electrode pad 160, which are illustrated in FIG.5.

TABLE 2 First Second Third Through Through Through Electrode ElectrodeElectrode Distance (μm) 163.8 568.8 973.8 from Electrode Pad Radius (μm)25.0 26.7 29.3 of Via-hole Width (μm) of 12 12 12 First AdjustingPortion Radius (μm) 13 14.7 17.3 of First Region Area (μm²) 530.9(100%)678.9(127.9%) 940.2(177.1%) of First Region

According to the present disclosure, the light-emitting element 100B hasa structure in which diameters of the through electrodes (or thevia-holes) increase going away from the electrode pad 160 and exposedareas of the first regions 131 a increase. In this case, diameters ofsecond adjusting portions 141 b of the first insulating layers 141increase. Therefore, diameters of the first insulating layers 141 mayincrease going away from the electrode pad 160 (W₃₃>W₃₂>W₃₁), and widthsof the second conductive layers 120 disposed between the secondadjusting portions 141 b may decrease (L₁>L₂).

In this drawing, the first region and the first insulating layer areillustrated as a circular shape, but the present disclosure is notlimited thereto. The first region and the first insulating layer mayhave a polygonal or line shape.

Third Embodiment

FIG. 7 is a plan view of a light-emitting element according to a thirdembodiment of the present disclosure, FIG. 8 is a cross-sectional viewtaken along line C-C of FIG. 7, FIG. 9 is a partially enlarged view ofportion S₂ of FIG. 8, and FIGS. 10A to 10F are cross-sectional viewsillustrating a method of manufacturing the light-emitting elementaccording to the third embodiment of the present disclosure.

Referring to FIGS. 7 and 8, a light-emitting element 100C according tothe third embodiment of the present disclosure includes a light-emittingstructure 110 including a first semiconductor layer 111, an active layer112, and a second semiconductor layer 113, a first conductive layer 130including a plurality of through electrodes 131 electrically connectedto the first semiconductor layer 111, a second conductive layer 120which is electrically connected to the second semiconductor layer 113and is disposed between the through electrodes 131, a plurality ofinsulating layers 140 which electrically insulate the plurality ofthrough electrodes 131 from each other, and an electrode pad 160disposed in an exposed region of the second conductive layer 120.

The first conductive layer 130 is electrically connected to the firstsemiconductor layer 111. Specifically, the first conductive layer 130may include the plurality of through electrodes 131. The throughelectrodes 131 may be disposed in via-holes 115 formed in thelight-emitting structure 110. The first conductive layer 130 may beelectrically connected to a conductive substrate 150 disposedtherebelow.

The second conductive layer 120 is electrically connected to the secondsemiconductor layer 113. The second conductive layer 120 may be disposedin regions between the plurality of through electrodes 131. The secondconductive layer 120 may be electrically connected to the electrode pad160 by exposing one region thereof.

Each of the insulating layers 140 may include a first insulating layer141 which electrically insulates the through electrodes 131 from theactive layer 112 and the second semiconductor layer 113, and a secondinsulating layer 142 which electrically insulates the second conductivelayer 120 from the first conductive layer 130. Therefore, each of theinsulating layers 140 may have an increased thickness in a region inwhich the first insulating layer 141 and the second insulating layer 142overlap.

However, the present disclosure is not limited thereto, and the firstinsulating layer 141 and the second insulating layer 142 may beintegrally formed. The first insulating layer 141 and the secondinsulating layer 142 may be integrally formed by first forming thesecond conductive layer 120 on the second semiconductor layer 113 andthen forming the via-holes 115.

Diameters of the first insulating layers 141 may decrease going awayfrom the electrode pad 160 (W₃₁>W₃₂>W₃₃), and widths L₁ and L₂ of thesecond conductive layers 120 may increase going away from the electrodepad 160 on an imaginary line C-C (in FIG. 7) which connects theplurality of through electrodes 131 in the electrode pad 160 (L₂>L₁).That is, the widths of the second conductive layers 120 divided by theplurality of through electrodes 131 on the imaginary line may bedifferent from each other. In this case, all widths of the first regions131 a may be the same.

Generally, in a region adjacent to the electrode pad 160, density ofholes is so high that relatively strong luminescence coupling may occur.Therefore, current crowding may occur in the region adjacent to theelectrode pad 160. On the other hand, in a region further away from theelectrode pad 160, density of holes is so low that relatively weakluminescence coupling may occur. Therefore, light emission uniformity ofthe entire light-emitting element may be reduced.

In the third embodiment of the present disclosure, density of holes in aregion in which luminescence coupling is strong, that is, a region closeto the electrode pad 160, is reduced and thus current crowding may bereduced.

Further, density of holes in a region relatively far from the electrodepad 160 is increased and thus luminescence coupling may be increased.Therefore, since luminescence coupling in a region close to theelectrode pad 160 becomes relatively lower and luminescence coupling ina region far from the electrode pad 160 is increased, uniform lightemission may be achieved throughout.

Referring to FIG. 9, each of the first insulating layers 141 may includea first adjusting portion 141 a which exposes the first region 131 a,and a second adjusting portion 141 b which covers a portion of thesecond semiconductor layer 113. The width of the second conductive layer120 may be adjusted by the width of the second adjusting portion 141 b.

For example, widths of the second adjusting portions 141 b may graduallydecrease going in a direction of an arrow D (W₂₃<W₂₂<W₂₁). When thesecond adjusting portions 141 b have a ring shape, diameters of thesecond adjusting portions 141 b may decrease going in the direction ofthe arrow D. As a result, a diameter W₃ of the first insulating layer141 decreases going in the direction of the arrow D, and an area of thesecond conductive layer 120 disposed between the first adjustingportions 141 a increases. Therefore, a width of the second conductivelayer 120 in a region closest to the electrode pad 160 becomesrelatively lower, and thus density of holes in the region closest to theelectrode pad 160 may be reduced and density of holes in the regionrelatively far from the electrode pad 160 may be increased.

In the drawing, the first region and the first insulating layer areillustrated as a circular shape, but the present disclosure is notlimited thereto. The first region and the first insulating layer mayhave a polygonal or line shape.

Referring to FIG. 10, a method of manufacturing a light-emitting elementaccording to the third embodiment of the present disclosure includesforming the via-holes 115 in the light-emitting structure 110, formingthe first insulating layers 141 in the via-holes 115, forming the secondconductive layer 120 on the second semiconductor layer 113 between thefirst insulating layers 141, forming the second insulating layer 142 onthe second conductive layer 120, forming the first conductive layer 130including the through electrodes 131 disposed in the via-holes 115,forming the conductive substrate 150 electrically connected to the firstconductive layer 130, and forming the electrode pad 160 by exposing aportion of the second conductive layer 120.

Referring to FIG. 10A, in the forming of the light-emitting structure,the first semiconductor layer 111, the active layer 112, and the secondsemiconductor layer 113 are formed on an insulating substrate 114, andthe plurality of via-holes 115 passing from the second semiconductorlayer 113 to a portion of the first semiconductor layer 111 are formed.Diameters of the via-holes 115 may be the same.

Referring to FIG. 10B, in the forming of the first insulating layers141, the first insulating layers 141 may be formed in the via-holes 115using a mask pattern (not illustrated). Each of the first insulatinglayers 141 may include a second adjusting portion 141 b formed to extendto a portion of the second semiconductor layer 113. In this case, widthsof the second adjusting portions 141 b may be different from each other.

Specifically, referring to FIG. 10B, the width of the second adjustingportion 141 b disposed at the right side may be the largest, and thewidths of the second adjusting portions 141 b may decrease going towardthe left. Therefore, distances between the second adjusting portions 141b increase toward the left (L₂>L₁).

Referring to FIG. 10C, in the forming of the second conductive layer120, the second conductive layer 120 may be formed on the secondsemiconductor layer 113 exposed between the first insulating layers 141.The second conductive layer 120 may serve as a reflective layer. Withthe above-described configuration, an area of the second conductivelayer 120 increases toward the left (L₂>L₁). Then, in the forming of thesecond insulating layer 142, the second insulating layer 142 may beformed on the second conductive layer 120 to seal the second conductivelayer 120. To this end, an end portion of the second insulating layer142 may be in contact with the first insulating layer 141. Therefore, athickness of a portion in which the first insulating layer 141 and thesecond insulating layer 142 are into contact with each other mayincrease.

Referring to FIG. 10D, in the forming of the first conductive layer, theplurality of via-holes 115 are filled with electrodes to form thethrough electrodes 131. The first conductive layer 130 may connect theplurality of through electrodes 131 to each other.

Referring to FIG. 10E, in the forming of the conductive substrate, theconductive substrate 150 is formed on the first conductive layer 130. Inthis case, the insulating substrate 114 of the light-emitting structure110 may be removed. A laser lift-off method may be used as a method ofremoving the insulating substrate 114, but the present disclosure is notlimited thereto. In this case, an uneven portion may be formed on anupper surface of the light-emitting structure 110 as necessary.

Referring to FIG. 10F, in the forming of the electrode pad 160, one sideof the light-emitting structure 110 is etched (M) to expose the secondconductive layer 120, and the electrode pad 160 may then be formedthereon. A separate protective layer 170 may be formed on side surfacesof the light-emitting structure 110.

Fourth Embodiment

FIG. 11 is a plan view of a light-emitting element according to a fourthembodiment of the present disclosure, and FIG. 12 is a cross-sectionalview taken along line D-D of FIG. 11.

Referring to FIGS. 11 and 12, a light-emitting element 100D according tothe fourth embodiment of the present disclosure includes alight-emitting structure 110 including a first semiconductor layer 111,an active layer 112, and a second semiconductor layer 113, a firstconductive layer 130 including a plurality of through electrodes 131which are electrically connected to the first semiconductor layer 111, asecond conductive layer 120 which is electrically connected to thesecond semiconductor layer 113 and is disposed between the throughelectrodes 131, a plurality of insulating layers 140 which electricallyinsulate the plurality of through electrodes 131 from each other, and anelectrode pad 160 disposed in an exposed region of the second conductivelayer 120.

The components may be same as those in the third embodiment describedabove, but a configuration in which an area of the second conductivelayer 120 is adjusted is different from that in the third embodimentdescribed above. Therefore, the configuration in which the area of thesecond conductive layer 120 is adjusted will be described in detail.

Distances between the through electrodes 131 may increase going awayfrom the electrode pad 160 (L₆>L₅). Therefore, the area of the secondconductive layer 120 increases going away from the electrode pad 160(L₄>L₃). A length of a second insulating layer 142 also increases toinsulate the second conductive layer 120 therefrom.

In the drawing, the first region and the first insulating layer areillustrated as a circular shape, but the present disclosure is notlimited thereto. The first region and the first insulating layer mayhave a polygonal or line shape.

Fifth Embodiment

FIG. 13 is a cross-sectional view of a light-emitting element accordingto a fifth embodiment of the present disclosure.

Referring to FIG. 13, in a light-emitting element 100E according to thefifth embodiment of the present disclosure, areas of first regions ofthrough electrodes 131 may increase going away from an electrode pad 160(P₃>P₂>P₁), and an area of a second conductive layer 120 may alsoincrease going away from the electrode pad 160 (L4>L3). According tosuch a configuration, since a charge injection area and a hole injectionarea are simultaneously reduced in a region adjacent to the electrodepad 160, current crowding may be further reduced.

There is no limitation on a configuration for controlling an area of thefirst region 131 a and an area of the second conductive layer 120. Forexample, the area of the first region 131 a may be controlled accordingto the first embodiment and the area of the second conductive layer 120may be controlled according to the third embodiment. Alternatively, thearea of the first region 131 a may be controlled according to the secondembodiment and the area of the second conductive layer 120 may becontrolled according to the fourth embodiment.

A plurality of light-emitting elements according to the first to fifthembodiments may be disposed on a substrate in an array, and an opticalmember such as a light guide plate, a prism sheet, a diffusion sheet, orthe like may be disposed on a light path of a light-emitting elementpackage. The light-emitting element package, the substrate, and theoptical member may function as a backlight unit.

Further, the light-emitting element package, the substrate, and theoptical member may be implemented as a display device, an indicationdevice, or a lighting device including the light-emitting elementpackage according to the embodiment.

Here, the display device may include a bottom cover, a reflective platedisposed on the bottom cover, a light-emitting module which emits light,a light guide plate which is disposed in front of the reflective plateand guides light emitted from the light-emitting module forward, anoptical sheet including a prism sheet disposed in front of the lightguide plate, a display panel disposed in front of the optical sheet, animage signal output circuit which is connected to the display panel andsupplies an image signal to the display panel, and a color filterdisposed in front of the display panel. Here the bottom cover, thereflective plate, the light-emitting module, the light guide plate, andthe optical sheet may form a backlight unit.

Further, the lighting device may include a light source module includinga substrate and the light-emitting element package according to theembodiment, a heat radiator for radiating heat of the light sourcemodule, and a power supply for processing or converting an electricalsignal provided from the outside and providing the electrical signal tothe light source module. For example, the lighting device may include alamp, a head lamp, or a street lamp.

The head lamp may include a light-emitting module including alight-emitting element package disposed on a substrate, a reflectorwhich reflects light emitted from the light-emitting module in apredetermined direction, for example, forward, a lens which refracts thelight reflected by the reflector, and a shade which blocks or reflects aportion of the light reflected by the reflector and is directed to thelens to provide a desired light distribution pattern of the designer.

While the present disclosure has been mainly described with reference tothe embodiments, and it should be understood that the present disclosureis not limited to the disclosed exemplary embodiments, and that variousmodifications and applications can be devised by those skilled in theart without departing from the gist of the present disclosure. Forexample, each component specifically shown in the embodiment can bemodified and implemented. Differences related to these modifications andapplications should be construed as being within the scope of thepresent disclosure defined by the appended claims.

1. A light-emitting element comprising: a light-emitting structureincluding a first semiconductor layer, an active layer, and a secondsemiconductor layer; a second conductive layer electrically connected tothe second semiconductor layer; a first conductive layer including aplurality of through electrodes which are disposed in a plurality of viaholes passing through the light-emitting structure and the secondconductive layer and are electrically connected to the firstsemiconductor layer; an insulating layer configured to electricallyinsulate the plurality of through electrodes from the active layer, thesecond semiconductor layer, and the second conductive layer; and anelectrode pad disposed in an exposed area of the second conductivelayer, wherein widths of the second conductive layers disposed betweenthe plurality of through electrodes increase going away from theelectrode pad.
 2. The light-emitting element of claim 1, wherein theinsulating layer includes a plurality of first insulating layers, whichare respectively disposed in the plurality of via-holes and insulate thethrough electrodes from the active layer, the second semiconductorlayer, and the second conductive layer.
 3. The light-emitting element ofclaim 2, wherein the first insulating layer includes a first adjustingportion, which is a formed on a bottom surface of the via-hole andpartially exposes the bottom surface of the via-hole.
 4. Thelight-emitting element of claim 3, wherein the first insulating layerincludes second adjusting portions configured to extend from thevia-holes to the second semiconductor layer.
 5. The light-emittingelement of claim 4, wherein widths of the plurality of second adjustingportions decrease going away from the electrode pad.
 6. Thelight-emitting element of claim 4, wherein widths of the plurality offirst adjusting portions are the same.
 7. The light-emitting element ofclaim 4, wherein the second conductive layer is disposed between thesecond adjusting portions.
 8. The light-emitting element of claim 7,wherein the insulating layer includes a second insulating layerconfigured to electrically insulate the plurality of second adjustingportions from the first conductive layer.
 9. The light-emitting elementof claim 1, wherein distances between the plurality of throughelectrodes increase going away from the electrode pad.
 10. Thelight-emitting element of claim 9, wherein the insulating layer includesa first adjusting portion, which is formed on a bottom surface of thevia-hole and partially exposes the bottom surface of the via-hole. 11.The light-emitting element of claim 10, wherein the insulating layerincludes a second adjusting portion configured to extend from thevia-hole to the second semiconductor layer.
 12. The light-emittingelement of claim 11, wherein widths of the plurality of first adjustingportions are the same.
 13. The light-emitting element of claim 11,wherein widths of the plurality of second adjusting portions are thesame.
 14. The light-emitting element of claim 9, wherein widths of theplurality of first adjusting portions decrease going away from theelectrode pad.
 15. The light-emitting element of claim 1, furthercomprising a conductive substrate electrically connected to the firstconductive layer.